Core taking apparatus



Jan. 1,1952 5; BRADY 2,580,510

CORE TAKING APPARATUS I Filed May 13, 1948 2 Sl-IEETSSHEET l L 1 15 Z0w-\- I Q 5 F" R I 5-- o I i Y 1 g E E g 55 X I "12 v 3mm Edward FaB Brads E. F. BRADY 2,580,510

CORE TAKING APPARATUS 2 smams-smw 2 & 5 W M we 6 5 7 5 2 Z 1 5 5 7 Z M M [In r 3m 9 L RV ::-i\ L k I J E. w .m K I W Q w fi Jan. 1, 1952 Filed May 13, 1948 Z 6 ,W 5 0 m a a 55 w w. a 8 4 Z I I H l a J9 7 4 6 D Z z z Patented Jan. 1, 1952 001m TAKING APPARATUS Edward Fay Brady,Long Beach, Calif., assignor to Eastman Oil Well Survey Company, Denver, 0010., a corporation of Delaware Application May 13, 1948, Serial N 0. 26,785

This invention relates to new and useful improvements in core taking apparatus and particularly to an improved core-receiving assembly for use with such apparatus.

In the drilling of petroleum wells, it is general and well known practice to cut or take a. core or sample of the sub-surface formation or strata during the actual drilling operation by means of a coring apparatus which includes a core drill. The ordinary core drill is provided with a central bore and thecore passes upwardly through said bore into a core-receiving assembly which retains said core therein. When brought to the surface the core is removed from the core-receiving assembly and may be examined to determine the dip and strike of the underground strata. It is, of course, essential that the core-receiving assembly eifectively retain the entire core so that it may be fully recovered for subsequent examination; also, it is desirable that the core be marked in some manner so that it may beproperly oriented to provide accurate information regarding the sub-surf ace structure.

It is one object of thepresent invention to provide an improved core-receiving assembly which is so constructed that the core being cut or taken will readily pass upwardly thereinto and which has means for properly marking or scribing said core for orientation purposes.

An important object of the invention is to provide an improved core-receiving assembly which will effectively retain a relatively soft core and which will just as readily retain a relatively hard core, whereby it may be 'efliciently employed in coring operation in all types of formations.

H Still another object of the invention is toprovide a core-receiving assemblyhaving improved means for engaging and retaining a core of the Claims. (Cl. 25572) sub-surface strata or formation which means also functions to efficiently break ofi or detach said core when the assembly is removed from the well to bring the'c'ore or sample to the surface for visual examination.

A still further object of the invention is to tween; said retaining elements being adapted to co-act with the usual core drill, whereby said elements are moved radially inwardly into engagement with the core, whereby said elements function to assure clean breaking off or detaching of said core and a subsequent retention thereof within the core-receiving tube, the arrangement being particularly useful in the taking of cores in relatively hard formations.

The construction designed to carry out the invention will be hereinafter described together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawing, wherein an example of the invention is shown, and wherein:

Figure 1 is a view partly in section and partly in elevation showing the improved apparatus mounted within a drill string,

Figure 2 is a partial isometric view of the improved core-receiving tube,

Figure 3 is a partial isometric view of the lower portion of the tubular section which connects the core-receiving tube with the remainder of the apparatus,

Figure 4 is an enlarged, transverse, sectional view of the core-receiving assembly illustrating the same in position during the cutting of a core,

Figure 5 is a similar view illustrating the coaction between the retaining elements of the as sembly with the core bit to illustrate the breaking off or detachment of a core from the formation, and

Figure 6 is a horizontal, cross-sectional view taken on the line 6-6 of Figure 4.

In the drawings, the numeral 10 designates a drill, pipe or string which extends axially through the well bore (not shown). A drill bit II of any desired construction is connected to the lower end of the drillpipe or string and the body of saidbit is substantially hollow with an axial opening l2 in its lower portion. The bit is provided with the usual cutting blades l3 and circulation ports l4.-

The present invention resides in the core-receiving tube assembly which is generally indicated at A and said assembly is illustrated as combined with the removable core-taking apparatus described in the application of Charles T. Engle, Serial No. 631,052, filed November 27, 1945, now Patent No. 2,489,566. However, it is noted that the improved core-receiving assembly A may be employed with any standard core-taking equipment.

As illustrated; the assembly A has its upper end connected through a coupling [5 with a tubular barrel l6 within which a survey instrument S is mounted. The barrel l6 and core-receiving assembly A are disposed axially within an elongate tubular casing or housing- I'Ltheupp'er end of which is provided with a retractable latch mechanism l8, whereby the housing I! may be rotatably connected to the drill pipe It]. A spear head [9 which is adapted to be engaged by a suitable fishing tool (not shown) carried by a wire line or cable is associated with the latch mechanism [8 and permits the casing I! to be lowered-and retracted.- from thedrill stem by means of such wire line or cable. The barrel it which houses the instrument and the improved core-receiving assembly A are rotatably mounted with respect to the tubular casing or housing I! by a suitable bearing 20.

The removable casing or housing H within which the core-receiving assembly A .is'mounted has a core bit 2l'secu1'ed to its lower end and when the casing is in latched position within the drill stem In, an external annular shoulder 22 on the core bit body engages or rests upon an annular seat 12a provided within the drill bit II. This permits the lower portion of the corebit to extend outwardly through the. bore 1.2a. in the drill bit and the extreme lower end of the core bit is formed with suitable cutting teeth 23. The core bit-is provided with an axial bore-24 extending entirely therethrough and the intermediate portion of said bore is generally inclined or'-.tapered outwardly asindicated at 25. Suitable circ'ulation ports 26a extend through the wallof the core bit.

It will be evident that with the casing ll rm tatably vlatchedin position within the drill pipe |0,'a rotation of said pipe will impart rotation to the drill bit and also to the'core bit. As'drilling proceeds acore is cutby-the bit'l2l and passes upwardly into' the bore'. 24 thereof. The improvedcore-receiving assembly .Ahas its lower portion projecting downwardly .into'ithe bore. of

the core bit and thus the core entering said bore passes upwardly into the assemblyA. ..Because of. .the rotatable. bearing connection Zil'betweeh the instrument barrel I 6 and the housing or leasing l1, it will be obvious .thatthe core-receiving assembly. A may remain. stationary, while-the casing H and .the' drill pipe it) are .rotated'during the cutting operation.

The improved core receilving assembly: .A is clearly shown in Figures 2 to 6 and this assembly includes a core-receiving tube. 26 Whichnhas a substantially straight. bore 26?) extending .entirely therethrough. .A pluralityof. core ret'aining elements 27 in the form-ofrfiat spring bars have their upper endssuitablysecured-within thelower portion of the bore. Thee1em'ents12-1 are spaced equi-distant around. tube 26 .and may varyinnumber, with four beingiillustratedill Each element: or bar is provided with a pair of. inwardly directed sharpened dogs-23 atits lower end. An inwardly curved resilient spring member or finger 29.has its lower portion fastened to each retaining element and will function, as will beexplained, to retain cores of softer formation. Since the members 29 are secured to the inner faces'of the retaining elements 21, said members are spaced equi-distant radially from each other and as is clearly shown in Figure 4, the upper ends of the members or .fingers 29. project inwardly into the path of the core enteringthe tube 26.

For marking a core which enters theborez-Zfib of the tube 28 an elongate vertical scriber or bar 3;] is suitably mounted within a radial slot'3l formed in the wall of the tube. This scriber may have its inner surface formed with teeth or serrations to assure effective marking of cores of harder formations.

The upper end of the bore of the tube is enlarged slightly as indicated at 28c and this portion of said tube has a telescoping or slip iit over the lower end of an upper tubular section 33.

its upperiend. adapted toaengagewithin a slot 35 which is formed in the lower portion of the tubu' .clar section 33 when the tube telescopes said section. It is noted that the telescoping or slip fit between the tube 26 and the section 33 is a rela- ,tively tight frictionfit.

rlnutheoperation of the apparatus, the improved core-receiving assembly A is connected to the barrel 16 through the coupling H3. The

core receiving tube 26 is engaged with the lower endof :the tubular section 33 through the telescoping or slip joint and this connection causes the upper end of the marking bainor elementBE] to engage within the slot. 35 in section33. The assembly is then mounted within the outer tubularcasing or housing I! which has the core bit 2| threaded onto its lower end; With the. assembly disposed in position within the casing or housing IT, the lower ends of'the retaining elements or bars 21' which depend from the core receiving tube26 engage the inclined portion25 of thebore' of the'core bit. 2|. This position of the bits is illustrated in Figures 1 andi'4. The tubular casing I! is coupledlthrough thelatching mechanism I8 with'the drill. stem l0 and at this time thecore bit 2| projects through the bore" l2 of: the" drill bit i I; as is clearly showniniFigi ure 1. J The drilling'opera'tionis then-carriedout imparting rotation to1thedrill pipeorstem I]! and suchrot'ation is transmitted throughthe latch me'chanismI I8 andfltubular casing, ll-"to the-corebit 2|,,whereby a core of the formation is 'cut by said core bit. This corepassesupward: 1y through the bore of the" core bit and past the retaining elements 21 and spring fingers 29"into the interior or bore 261) of the tube 26. As the core passes upwardly into the core-receiving'tube 26 and its connected tubular section 33, the scriber or marking bar 30 functions to clearly mark said core. If the core .is one of a softer. formation, the resilient l curved fingers 29 which are secured to theinner surfaces of the retains ing elements '21 engage said. core. and. function to retain it within the. core-receiving tube. fiIt is noted thatthe spring fingers 29 have a. greater resiliency or. flexibility than the retaining elements 2], the latter having a certainv degreepf resilienc'ybut' actually being stiifenthanpthe ..Experience has shown thatin many casesit is difficult to obtain a sharp breaking off of. the core which has entered the tubeand thisis par-. ticularly true when the core is=of a harder formotion. The particular apparatus disclosed makesitpossible to detach orv break off the .core

when it is desired to retrieve the same. The connection between the assembly A and its connected barrel IS with the tubular casing or housmg I! is such that not only can the casing rotate with respect to the assembly and barrel IE but also, the casing may undergo a limited longitudinal movement with respect to said barrel and said assembly. This is possible because the connecting pin a above the bearing 2|] is shorter than the recess 20b in the casing 11. Thus, when it is desired to retrieve the core, a suitable fishing tool is engaged with the spear head I!) and an upward pull is'exerted upon the spear, Such upward pull first releases the latching mechanism l8 and then imparts an upward movement to the casing I1 and the core bit 2|.

Since the core is still attached to the formation at this time and since it is in frictional engagement with the retaining bars 21, the tube and its connected parts are held stationary by such Therefore, the upward v pull on the casing I1 and the core bit 2! causes said bit to move upwardly with respect to thefrictional engagement.

retaining elements or bars 21 of the core-receiving tube 26. causes the inclined portion 25 of the bore of the core bit to co-act with the flexible retaining elements or bars 21 to move said elements or bars radially inwardly. Such inward movement of the bars21 forces the sharpened dogs '28 firmly into the core which is disposed therebetween and will result in a suflicient scoring of the core to assure breaking oif at this point. Continued upward movement will then retrieve the core with mits a coaction between the bore of the core bit Q with the retaining elements to urge said element inwardly into firm engagement with the core disposed therebetween. It is noted that although the arrangement whereby the elements 21 may be moved inwardly is especially advantageous in assuring proper breaking off of the harder cores the inward movement of the retaining elements is also desirable in urging the resilient fingers 29 into firmer engagement with the softer formation cores. The provision of the slip or telescoping joint between the tube 26 and its associated tubular section 33 makes it possible to easily remove the core which has been obtained after the apparatus is brought to the surface. As has been noted, it is desirable that the spring fingers 29 have greater flexibility than the retaining elements or bars 21; however, the latter have sufiicient inherent resiliency to assure their engagement with the core disposed therebetween at all times. It is again noted that although the improved core-receiving assembly has been shown with a particular type of core-taking apparatus, it may be employed with any of the well known core-taking equipment now in general use;

The foregoing description of the invention explanatory thereof and various changes in the size, shape and materials, as well as in the de,-. tails of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

This relative upward movement In either 6 'What I claim and desire to secure by Letters Patent is:

1. A core-receiving assembly for core-taking apparatus including, a core-receiving tube, a plurality of retaining elements mounted on the lower end of said tube and depending in a plane therebelow, said elements being constructed of metallic bars having an inherent resiliency urging them radially inwardly, sharpened dogs mounted on the extreme lower end of each element, a flexible spring finger secured to the inner surface of each element intermediate its ends, and an elongate scriber mounted in the wall of the tube between two of-the elements and having a toothed edge of considerable length extending radially inwardly into the bore.

2. A core-receiving assembly for use with a core-taking apparatus including, an elongate core-receiving tube, an associated tubular section having its lower end telescoping the upper end of the tube and frictionally engaged therewith, a scribe bar secured in the wall of said tube and directed radially inwardly into the bore thereof, said bar extending throughout the length of said tube and having its extremities projecting beyond the upper and lower ends thereof, the tubular section having a slot there in for receiving the upper projecting end of the bar when said section is connected with the tube, and a plurality of flexible retaining elements secured to the lower end of the tube and depending therefrom said elements being spaced at various radial points around said tube.

3. The combination with a core bit having a tapered axially extending bore, of a core receiving assembly including, a core receiving tube of considerable length to receive the core to be cut and mounted so as to be axially aligned with the bore of said bit and to permit limited relative movement between it and the bit, a plurality of retaining elements secured to the tube and extending downwardly into the tapered bore of the core bit, whereby a core cut by said bit and passing upwardly through the bore thereof and into the core receiving tube passes between the retaining elements and is engaged thereby, said elements contacting the tapered bore of said core bit and co-acting therewith upon a movement of the core bit relative to the elements and the tube, whereby said elements are moved radially inwardly, means on the extreme lower ends of said retaining elements for engaging and efiectively retaining a core of hard formations, and an elongate radially directed scribing means mounted in the wall of the core receiving tube and having a series of teeth on its inner edge projecting into the tube for marking the core entering said tube, said scribe being positioned between the retaining elements and of such length as to extend to a point beyond the upper ends thereof.

4. The combination with a core bit having a tapered axially extending bore, of a core receiving assembly including a core receiving tube of considerable length to receive the core to be cut and mounted so as to be axially aligned with the bore of said bit and to permit limited relative movement between it and the bit, a plurality of retaining elements secured to the tube and extending downwardly into the tapered bore of the core bit, whereby a core cut by said bit and passing upwardly through the bore thereof and into the core receiving tube passes between the retaining elements and is engaged thereby, said elements contacting the tapered bore of said core bit and co-acting therewith uponamovement'of the core bit relative to the elements and-the tube,

whereby said: elements are moved radially inwardly, .means on the extreme lowerends of said retaining elements for engaging and effectively retaining a core of soft formation, and an elongate radially directed scribing-means mounted in the wall of the-core receiving tube and having teeth on its inner edge which project into the tube for marking the core entering said tube, said scribe being'positioned between two retaining elements and extendingt na point beyond the upper ends thereof.

5. In well bore core taking apparatus for use with-a" drill pipe having a drill bit with an axially extending bore having a shoulder therein, a tubularv member provided witha core bit having an axially extending bore and an external shoulder above the core bit for engaging the shoulder in the drillbit bore, said tubular member and core bit being receivablenin and removable from the drill stem withoutremoving the drill pipe and 1 flexing the elements inwardly to engage a core upon relative axial movement between the-core barrel and the core bit. i EDWARD FAY BRADY.

. REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 7 Name "Date 315,888 Ball Apr. 14, 1885 1,582,904 Convey "May"4,192 6 1,994,847 Baker Mar. 19,1935 2,017,522 Bailey et a1. Oct. 15, 1935 2,132,014 Catland l; Och-4, 1938 2,234,286 Stokes Mar; 1-1, 1941 r 2,330,155 Stokes SeptJZl, 1943 2,499,543 Townsend Mar. 7, 1950 2,502,762 1950 Stokes -2 -Apr.= 4, 

